PERMITS
Illinois oversize permits are valid for five days and must be obtained before entering the state.
OPERATING HOURS
Permit loads up to 12 feet wide, 13 feet 6 inches high, and 200 feet in length may travel 24/7 with one civilian escort when operating at night. Loads up to 14 feet 6 inches wide, 15 feet high, and 200 feet long may travel daily from 30 minutes before sunrise to 30 minutes after sunset. Loads exceeding those dimensions are limited to Monday through Friday, 30 minutes before sunrise to 30 minutes after sunset, and on Saturdays from 30 minutes before sunrise until noon. Overweight-only loads with legal dimensions are allowed continuous travel unless otherwise stated on the permit.
RESTRICTED TRAVEL
Cook County expressways restrict permit loads to 120,000 pounds, 12 feet in width, and 13 feet 6 inches in height. Additional restrictions in Cook County are outlined in General Provisions B.
Loads 14 feet 6 inches wide up to 16 feet wide are restricted to travel from 9:00 AM to 3:00 PM, Monday through Friday, in the following counties: Cook, DuPage, Lake, Kane, Madison, McHenry, Monroe, St. Clair, and Will. Wider loads may be subject to additional restrictions. No permit travel is allowed after noon the day before major holidays or holiday weekends.
ILLINOIS TOLL ROADS
- Maximum width: 10 feet (12 feet allowed on I-80 and US-51 sections)
- Maximum gross weight: 120,000 pounds
- Loads over 100 feet in length require special approval
- Maximum height: 14 feet 6 inches (over 13 feet 6 inches adds $15 fee)
- Permit fees: $35 for 80,001–104,000 pounds; $150 for 104,001–120,000 pounds
LEGAL DIMENSIONS
Length:
- 53-foot semi-trailer on designated highways (with kingpin to rear axle center ≤ 45 feet 6 inches)
- 65 feet overall on non-designated roads
- Overhang: 3 feet front, 4 feet rear (additional rear overhang allowed if within legal limits)
Width:
- 8 feet 6 inches on designated highways
- 8 feet on non-designated roads
Height: 13 feet 6 inches
Gross Weight: 80,000 pounds
- Single axle: 20,000 pounds
- Tandem: 34,000 pounds
- Tridem: 42,500 pounds
ROUTINE PERMIT LIMITS
Length: 145 feet
Width: 14 feet 6 inches
Height: 15 feet (minimum 3-inch clearance required; no Interstate routing allowed above 15 feet 9 inches; over 16 feet requires a route survey)
Weight:
- Single axle: 24,000 pounds
- Tandem: 48,000 pounds
- Tridem: 60,000 pounds (no single axle over 21,000)
- Quad: 60,000 pounds (standard), up to 100,000 pounds (with superload permit)
Superload Guidelines:
An overweight application is treated as a superload if:
- 5 axles and gross weight exceeds 100,000 pounds, or over 44,000 on any tandem group
- 6+ axles and gross exceeds 120,000 pounds, or over 48,000 on any axle group
- For lift/pusher axles: Max weight difference between axles must not exceed 2,000 pounds
Loads exceeding any listed dimension or 16 feet in width or 17 feet in height require additional investigation or utility coordination.
EXEMPTIONS
No permit is required when transporting structural materials (beams, poles, pipe, culvert, etc.) up to 80 feet long and overall vehicle length does not exceed 100 feet, during weekdays. Implements of husbandry may be transported without a permit during daylight hours if overwidth only. A permit is still required if height exceeds 13 feet 6 inches or if the load is overweight.
ESCORT REQUIREMENTS
Length:
- Over 110 feet: 1 escort
- Over 145 feet: 3 escorts
- Over 200 feet: Illinois State Police required
Width:
- Over 14 feet 6 inches: 1 escort
- Over 16 feet: 3 escorts
- Over 18 feet: Illinois State Police required
Height:
- Over 14 feet 6 inches: 1 escort with high pole
- Over 16 feet: Route survey and 1 escort required
- Over 18 feet: 2 escorts plus Illinois State Police
If any two of these dimensions are exceeded, two escorts are required.
MISCELLANEOUS
- Lift axles are not considered for standard permits
- Equipment like blades, buckets, and counterweights may remain attached
- Two different oversize items cannot be combined on a single permit (e.g., a wide dozer and a tall backhoe)
SIGNS, FLAGS & LIGHTING
- Red flags are required on all extremities and projections
- "Oversize Load" signs are required when width exceeds 10 feet, height exceeds 14 feet 6 inches, or length exceeds 75 feet
- Amber rotating, flashing, or oscillating lights must be mounted on the tractor and visible from 500 feet in daylight
- If visibility is blocked from the rear or the load exceeds 80 feet (or 100 feet for combos), a second light must be placed within 10 feet of the rear of the load, mounted as high as possible
